Nokea
Concerning with NLRs, which of the following is NOT correct
- A. Are cytosolic receptors for MAMPs and DAMPs
- B. Include NOD receptors
- C. In Drosophila also important for embryonic development
- D. Similar proteins are also found in plants
Correct Answer: C
Rationale: The correct answer is C because NLRs are not important for embryonic development in Drosophila. NLRs are primarily involved in immune responses by recognizing pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) in the cytosol. Choice A is correct as NLRs are indeed cytosolic receptors for MAMPs and DAMPs. Choice B is correct as NOD receptors are a subset of NLRs. Choice D is correct as similar proteins to NLRs are also found in plants, known as NBS-LRR proteins. Therefore, the incorrect statement is C, as NLRs are not essential for embryonic development in Drosophila.
You may also like to solve these questions
An example of a preformed chemical barrier is:
- A. Mucus
- B. Lysozyme
- C. Tight junctions in epithelial cells
- D. Cilia in the respiratory tract
Correct Answer: B
Rationale: Step-by-step rationale:
1. Lysozyme is an enzyme that destroys bacterial cell walls.
2. This action acts as a preformed chemical barrier against pathogens.
3. Mucus (choice A) is a physical barrier, not a preformed chemical one.
4. Tight junctions (choice C) and cilia (choice D) are structural components, not chemical barriers.
Summary:
- Choice B, Lysozyme, is correct as it actively targets and destroys pathogens.
- Choices A, C, and D are incorrect as they do not directly function as preformed chemical barriers.
Dendritic cells play a role in:
- A. Costimulation of naïve T cells
- B. Processing of protein antigens to generate peptides
- C. Presentation of peptide-MHC complexes for recognition by T cell receptors
- D. All of the above
Correct Answer: D
Rationale: Dendritic cells play a crucial role in the immune system. Firstly, they provide costimulation to activate naïve T cells (A). Secondly, they process protein antigens into peptides for antigen presentation (B). Finally, dendritic cells present peptide-MHC complexes to T cell receptors for immune response activation (C). Therefore, the correct answer is D, as dendritic cells are involved in all these processes essential for initiating and regulating immune responses. Choices A, B, and C are incorrect as they are individual roles of dendritic cells and do not encompass the full range of functions that dendritic cells perform.
A patient with diarrhea has been diagnosed with Clostridium difficile. Along with standard precautions, which kind of transmission-based precautions will be used when the nurse is caring for this patient?
- A. Droplet precautions
- B. Contact precautions
- C. Isolation precautions
- D. Airborne precautions
Correct Answer: B
Rationale: Clostridium difficile spreads through direct contact with contaminated surfaces or hands. Therefore, contact precautions are necessary to prevent its transmission.
Individuals unable to make the J protein found in certain immunoglobulins would be expected to have frequent infections of the
- A. intestinal tract
- B. blood.
- C. liver.
- D. pancreas.
Correct Answer: A
Rationale: The correct answer is A: intestinal tract. The J protein is crucial for the proper functioning of immunoglobulins in the mucosal immune system, which plays a major role in defending against pathogens in the intestinal tract. Without the J protein, individuals would have impaired immune responses in the gut, leading to frequent infections in the intestinal tract. Choices B, C, and D are incorrect because the J protein deficiency specifically affects the mucosal immune system in the intestinal tract, not the blood, liver, or pancreas.
Which of the following enzymes removes 5' phosphate groups thereby preventing or decreasing the self-sealing of restricted plasmid vector molecules?
- A. Calf intestinal phosphatase
- B. Pyrophosphatase
- C. Phosphohydrolase
- D. phosphate exonuclease
Correct Answer: A
Rationale: The correct answer is A: Calf intestinal phosphatase. This enzyme removes 5' phosphate groups from DNA molecules, preventing self-ligation of restricted plasmid vectors. This step is crucial in generating linearized vectors for downstream applications. Pyrophosphatase (B) hydrolyzes pyrophosphate bonds, not 5' phosphate groups. Phosphohydrolase (C) is a general term for enzymes that hydrolyze phosphoester bonds, not specific to 5' phosphate removal. Phosphate exonuclease (D) degrades nucleic acids by removing nucleotides from the 3' end, not the 5' phosphate group.